Defender (Sanctuary #1) by Robert J. Crane

The world of Arkaria is a dangerous place, filled with dragons, titans, goblins and other dangers. Those who live in this world are faced with two choices: live an ordinary life or become an adventurer and seek the extraordinary.

Cyrus Davidon leads a small guild in the human capital of Reikonos.

Caught in an untenable situation, facing death in the den of a dragon, they are saved by the brave fighters of Sanctuary who offer an invitation filled with the promise of greater adventure.

Soon Cyrus is embroiled in a mystery – someone is stealing weapons of nearly unlimited power for an unknown purpose, and Sanctuary may be the only thing that stands between the world of Arkaria and total destruction.